Data storage devices such as optical storage disks and other optical storage media are increasingly being used to store digitized video, digitized music, digitized photographs, computer programs and other types of data. There are a large variety of types of data storage devices currently being used and others being developed. For example, among the currently most popular types of optical storage devices are compact disks (CD) and Digital Versatile Disks (DVD). CDs and DVDs can be in various formats such as read only memory (ROM), recordable (R), and read/write (RW).
Without some implementation of security, data stored on data storage devices can be freely copied and used. To discourage software copying, various types of low level security is used. For example, computer software sold on a disk may require a user to access a manual or a piece of paper on which a password key is printed. When software is loaded from the disk, the software prompts the user to type in the password key. Such security has the advantage of setting up some barriers to copying as well as being minimally burdensome to a user.
Security of the type described above is easily defeated by distributing a copy of the password key with a copy of data from the data storage device. Additionally, if the manual or piece of paper containing the password key is lost, this can significantly inconvenience a user.
U.S. Pat. No. 5,671,202 issued to Brownstein et al. and U.S. Pat. No. 6,081,785 issued to Oshima et al. disclose inscribing bar code symbols or other machine or human readable information over unused storage areas of a data storage surface of a compact disk.